One goal of the Healthy People 2010 program is to reduce health disparities across different segments of the population. Identification of language impairment (SLI) and careful description of its trajectory during the school-age years is one area where disparities continue to exist. One population that is currently understudied is the Spanish-English bilingual school population. Significant strides have been made in the identification of markers of language impairment in young bilingual (Spanish-English) children. There are emerging strategies and instruments that guide identification of true impairment vs. language differences in this population (e.g., Gutiirrez-Clellen, Restrepo, &Simon-Cereijido, 2006;Gutiirrez-Clellen &Simon-Cereijido, 2007). There is also more detail about the kinds of language changes that bilingual children make in their two languages as they transition from the home to the school language (Hammer, Lawrence, &Miccio, 2008). A number of studies examine reading outcomes in bilingual children as well. However, there is a lack of systematic longitudinal studies examining the consequences of SLI in bilingual children. Spanish speakers are the largest language minority in the US and they make up 79 percent of the school age limited English speaking population. During the school age years children need to move quickly from basic conversational skills in English to development of academic language skills. Yet, during the early second language acquisition, performance in each language is highly variable, demonstrated by inconsistent levels of fluency across each language (Bialystok, 2001). ELL children with SLI are at higher risk for low educational and linguistic outcomes. The higher risk comes from at least two major sources: (1) lack of English proficiency that limits academic access;and (2) their language impairment that puts them at-risk for other academic difficulties. We propose to examine developmental outcomes in three domains (phonology/phonotactics, vocabulary/semantics, morphosyntax) in bilingual children at three ability levels (SLI, typical developing-at risk, typically developing). This project has two main phases. In phase 1 we focus on risk for language impairment as a function of Spanish/English exposure and use patterns across three grades (preschool, first grade, and third). In phase 2 a multiple longitudinal design will be employed that will include 4 overlapping cohorts to span the preschool through 5th grade age range. We incorporate processing tasks tied to each domain designed to tap into children's ability to alter processing with experience (i.e., short term learning). Here, we focus on learning trajectories for bilingual children with and without SLI. The results will provide a unique perspective on the linking of development across domains (e.g., phonological skills supporting acquisition of morphosyntactic forms), within and across a bilingual child's languages, as well as how development is modulated by language exposure, impairment, and variations in production processes. PUBLIC HEALTH RELEVANCE: One goal of the Healthy People 2010 program is to reduce health disparities across different segments of the population. Identification of language impairment (SLI) and careful description of its trajectory during the school-age years is one area where disparities continue to exist. One large population that is currently understudied is the Spanish-English bilingual school population. We propose to study bilingual children with and without language impairment in order to reduce health disparities. Understanding the relationships among phonology, semantics, and morphosyntax will provide insights about possible supports these children need for making gains in their two languages. Documenting changes in language processing over time in both languages will contribute to the scientific knowledge base about expected trajectories.